1. Field of Invention
The invention relates to fasteners, namely threadless fasteners and more particularly to a threadless fastener for retaining two or more structures through apertures formed in each structure.
Detent pins are well known in industry. Many of these pins fall into the category of safety bolts. Safety bolts have a threaded end to which a nut can be attached to as well as a detent mechanism along the length of the bolt. The main fastening mechanism in safety bolts is threading the nut on the end of the bolt. These products are often used in the aircraft industry so an extra safety factor is present in case vibrations cause the nut to loosen or someone forgets to tighten the nut. The detent mechanism is this extra safety factor. However, these dual fasteners make safety bolts more difficult and thus more expensive to manufacture. Additionally there are some applications where such a bolt cannot be used because it is either impractical or impossible to access the threaded end of the bolt after it is inserted through an aperture. Also, screwing the nut on the end of the bolt causes an increase in assembly time.
Cotter pins are also well known in industry. A bolt with a cotter way is inserted through an aperture. A cotter pin is then inserted through the cotter way so the bolt cannot be removed from the aperture. It is thus obvious that access to the backside of the workpiece is necessary for a cotter pin to be utilized. Here again, insertion of the cotter pin in the cotter way is an extra step that will take more time during assembly.
There is a need in the market for a self-locking pin which is simple to manufacture and can be installed with little effort and in applications where there is no access to the opposing side of the workpiece and thus a nut cannot be applied to the threaded end of a pin.
2. Description of Prior Art
One type of prior art bolt is disclosed in U.S. Pat. No. 4,759,671 to Duran. Duran discloses a self-retaining bolt assembly in which the detent is a solid spherically shaped ball element with cut out sections and these cut out sections must be configured to saddle protuberances in the hole to prevent rotation. The periphery of the hole is peened in order to retain the detent in the hole. The shaft and detent of this bolt must both be machined carefully to assure a proper fit and retention for the detent.
Another prior art bolt is disclosed in U.S. Pat. No. 3,561,516 to Reddy. Reddy discloses a bolt with diametrically opposed detents slidably disposed in one hole. Each detent has a lateral passage with a sloped cam surface. These sloped cam surfaces engage a cam member which retains the detents in the hole. The detents are pulled into the hole when a force is exerted on the cam surface of the cam member by the cam surfaces of the detents. The detents are moved outwardly by the biasing means disposed between the detents. A number of carefully machined parts, which are difficult to install properly, are required. Additionally, the passageway extending along the axis of the bolt weakens the bolt.
A prior art bolt is disclosed in U.S. Pat. No. 2,361,491 to Nagin. Nagin disclosed a detent, generally circular in section, with a 45-degree slope at the upper end. A V-shaped groove with plane cam faces is formed in the body of the detent. The detent is slidably disposed in a hole in the shank. A circular passage extends along the bolt axis. A pin is slidably disposed in this passage. The pin is biased with a spring to engage the V-shaped groove and retain the detent in the hole. This bolt also must be carefully machined and installed to operate correctly. Additionally the passage in the shaft weakens the bolt.